// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_AUDIO_ANDROID_OPENSLES_INPUT_H_
#define MEDIA_AUDIO_ANDROID_OPENSLES_INPUT_H_

#include <SLES/OpenSLES.h>
#include <SLES/OpenSLES_Android.h>
#include <stdint.h>

#include <memory>

#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/synchronization/lock.h"
#include "base/threading/thread_checker.h"
#include "media/audio/android/opensles_util.h"
#include "media/audio/audio_io.h"
#include "media/base/audio_parameters.h"

namespace media {

class AudioBus;
class AudioManagerAndroid;

// Implements PCM audio input support for Android using the OpenSLES API.
// This class is created and lives on the Audio Manager thread but recorded
// audio buffers are delivered on an internal OpenSLES audio thread. All public
// methods should be called on the Audio Manager thread.
class OpenSLESInputStream : public AudioInputStream {
public:
    static const int kMaxNumOfBuffersInQueue = 2;

    OpenSLESInputStream(AudioManagerAndroid* manager,
        const AudioParameters& params);

    ~OpenSLESInputStream() override;

    // Implementation of AudioInputStream.
    bool Open() override;
    void Start(AudioInputCallback* callback) override;
    void Stop() override;
    void Close() override;
    double GetMaxVolume() override;
    void SetVolume(double volume) override;
    double GetVolume() override;
    bool SetAutomaticGainControl(bool enabled) override;
    bool GetAutomaticGainControl() override;
    bool IsMuted() override;

private:
    bool CreateRecorder();

    // Called from OpenSLES specific audio worker thread.
    static void SimpleBufferQueueCallback(
        SLAndroidSimpleBufferQueueItf buffer_queue,
        void* instance);

    // Called from OpenSLES specific audio worker thread.
    void ReadBufferQueue();

    // Called in Open();
    void SetupAudioBuffer();

    // Called in Close();
    void ReleaseAudioBuffer();

    // If OpenSLES reports an error this function handles it and passes it to
    // the attached AudioInputCallback::OnError().
    void HandleError(SLresult error);

    base::ThreadChecker thread_checker_;

    // Protects |callback_|, |active_buffer_index_|, |audio_data_|,
    // |buffer_size_bytes_| and |simple_buffer_queue_|.
    base::Lock lock_;

    AudioManagerAndroid* audio_manager_;

    AudioInputCallback* callback_;

    // Shared engine interfaces for the app.
    media::ScopedSLObjectItf recorder_object_;
    media::ScopedSLObjectItf engine_object_;

    SLRecordItf recorder_;

    // Buffer queue recorder interface.
    SLAndroidSimpleBufferQueueItf simple_buffer_queue_;

    SLDataFormat_PCM format_;

    // Audio buffers that are allocated in the constructor based on
    // info from audio parameters.
    uint8_t* audio_data_[kMaxNumOfBuffersInQueue];

    int active_buffer_index_;
    int buffer_size_bytes_;

    bool started_;

    std::unique_ptr<media::AudioBus> audio_bus_;

    DISALLOW_COPY_AND_ASSIGN(OpenSLESInputStream);
};

} // namespace media

#endif // MEDIA_AUDIO_ANDROID_OPENSLES_INPUT_H_
